Variable length bolt lever



July 29,1958

R, H. COLBY ARIABLE LENGTH BOLT LEVER Filed Nov. 17, 1955 HMH JNVENTOR.Ri Bhurd H- I: mlhy BY 9Z5 ,flzmiw HTTOENE Y5 cartridges therein.

2,844,903 VARIABLE LENGTH BOLT LEVER Richard Colby, South Hadley, Mass.,assignor to the United States of America as represented by the Secre-ZiaI'yOEtheArmy I 4 Application November 17, 1955, Serial No. 547,591 fj a 4 Claims. (c1. 42+16 p (Granted under Title 35, U. S. Code (1952),sec. 266) The invention described herein may be manufactured and used byor for the Government for governmental purposes without the payment ofany royalty thereon.

My invention relates toa bolt-operated gun and more particularly to sucha gun having a telescoping device for actuating the bolt thereof.

A conventional machine gun includes a receiver, and a recoil unit biasedto a battery position therein and provided with a barrel for batteryposition discharge of The recoil unit is disposed for reciprocaloperation responsive to the discharge and provided with an arm pivotedon the recoil unit and a slidable bolt for gripping the cases of thecartridges having a slideway for engaging the arm at the free endthereof. The arm is disposed for engagement with a receiver cam forsynchronous operation of the bolt to extract the cases from the barrelresponsive to the rearward portion of the reciprocal operation. Anejector stop in the feed portion of the receiver engages the cases inthe rearward strokesof the bolt to rotate the cases out of the bolt, andthe cases pass through an ejection port in the bottom of the receiver.

The distance between the stop and the port is substantially two andone-half inches, and the cases are slightly more than two inches longallowing the cases to rotate inside the gun. Because of the uncheckedrotation within the gun, cases have been known to strike the arm, and onthe forward stroke of the bolt to become jammed in the receiver andcause malfunction of the gun.

It is an object of my invention to provide such a gun with a receiver ofminimum height to curtail rotation of the cases within the gun.

Another object of my invention is to limit the space between the ejectorstop and the ejection port to less than the length of a cartridge casefor projection of the cases from the gun during the rotation.

A further object of my invention is to provide such a gun with atelescoping arm for actuating the bolt of the gun to decrease the heightof the receiver for decrease in the displacement between the stop andthe ejection port of the gun.

A still further object of my invention is to provide such a gun having aminimum height for minimum silhouette of the gun.

Other aims and objects of my invention will appear limited to less thanthe length of a cartridge case to ensure projection of the cases throughthe ejection port in the first ninety-degrees of revolution of the casesfrom the stop. The cases either pass directly through the ejec-' tionport or rebound from engagement with the bottom of the receiver to leavethe gun. Interference with the arm in this construction would tend topropel the case from the gun in the forward stroke'of thebolt.

The net decrease in dimensions of the receiver, the} recoil unit, andthe bolt results in a significant decrease in the weight andsilhouetteof the gun, both. of which results are highly desirable intheart of guns.

For a more complete understanding of my invention reference is directedto' the following description and the accompanying drawing in which: I

Fig. 1 is an elevation partly cut away of I porating an embodiment of myinvention with the bolt in battery position;

Fig. 2 is a view similarto Fig. 1 with the bolt in re tracted position;and

Fig. 3 is a view similar to Figs. 1 and 2 with the crank in themidposition thereof.

Accordingly, a weapon 12 having a receiver 14 includes a recoil unit 16biased to a battery position in the receiver 20 in reciprocal strokeoperation in slots 29 responsive to the reciprocation.

Crank 24 includes an arm with a hollow hub portion 28 and an extension30 is provided with rollers 32 engageable in portion 28 and pivotablyconnected at 34 to bolt 20 to permit extension 30 to slide inand out ofportion 28 during the reciprocal stroke operation.

Bolt 20 is constructed to grip case 36 of cartridge 22 and an ejectorstop 38 is disposed on receiver 14 for rotation of cases 36 from bolt 20in the rearward strokes thereof to permit the cases to pass through anejection port 40 in the bottom of receiver 14. The length of cartridgecases 36 is slightly more than two inches and the distance between stop38 and port 40 is substantially one and one-half inches. As shown inFig. 2, the front ends of cases 36 project through port 40 duringrotation from stop 38 and the cases are ejected from gun 12 even if thefront ends impinge on the bottom of receiver 14. Arm 28 tends to aidejection of cases 36 in the forward stroke of bolt 20.

Although a particular embodiment of the invention has been described indetail herein, it is evident that many variations may be devised withinthe spirit and scope thereof and the following claims are intended toinclude such variations.

I claim:

1. In a gun including a receiver with a cartridge ejection port in thebottom thereof, a cam provided in the receiver, a feeder on the receiverfor inclosing cartridges, a recoil unit slidably disposed in thereceiver for reciprocal operation, a barrel, and a bolt in the recoilunit respec- .tively disposed to chamber the cartridges and to retainthe chambered cartridges in the barrel in the battery position fordischarge thereof, a crank device for operating the bolt comprising anarm provided on the recoil unit for engagement with the cam, and anextension se said arm is provided with a hollow portion engageable bysaid rollers for telescopic operation.

3. A gun comprising a receiver with a cartridge ejection port in thebottom thereof, a cam provided in said 2,844,903 Patented July 29, 1958a gun incorreceiver, a feeder for inclosing cartridges disposed in saidreceiver, a recoil unit slidably disposed in said receiver forreciprocal operation, a barrel and a bolt disposed on said recoil unitrespectively to chamber the cartridges and to retain the chamberedcartridges in said' barrel in the battery position for dischargethereof, and a crank pivoted on said recoil unit for engagement withsaid cam and provided with an extension secured to said bolt, said cambeing disposed for reciprocal operation of said bolt during thereciprocal operation of said recoil unit and said extension beingdisposed for telescopic operation during the reciprocal operation formaintaining contiguous relation of said feeder and said recoil unit.

4. A gun as described in claim 3 with said receiver provided with a stopadjacent the path of said bolt to References Cited in the file of thispatent UNITED STATES PATENTS 309,834 Elliot Dec. 30, 1884 642,018Ternstrom Jan. 23, 1900 1,472,737 Ryan Oct. 30, 1923 2,093,705 BrowningSept. 21, 1937 2,411,979 Rataiczak Dec. 3, 1946

